code: def testRaisesErrorIfEndStepIsNegative(self):
      with self.assertRaises(ValueError):
          pruning_schedule.PolynomialDecay(0.4, 0.8, 10, -1)
  
imports: from absl.testing import parameterized
  import tensorflow
  from tensorflow_model_optimization.python.core.keras import compat
  from tensorflow_model_optimization.python.core.quantization.keras import utils
  from tensorflow_model_optimization.python.core.sparsity.keras import pruning_schedule
label_desc: Use image node_id 1 for calling the PolynomialDecayTest obj's underlying member method code with example usage: obj.testRaisesErrorIfEndStepIsNegative() without return types